Based on talks given to the Nottingham Shakespeare Society, 1999 - 2019. As the title suggests, the book is based on my life-long belief that the plays of Shakespeare are not only still relevant but more than ever essential to the survival of humanity in the twenty-first century. Unlike the rather vague and now largely discredited liberalism of the last half century, it is Shakespeare's ability to portray both human goodness and evil, and to show how we need the courage to embrace what is good even when it seems to achieve little, that is key to our future. This third edition, while still based on the original talks, is re-edited and re-ordered to make a more consistent argument and eliminate much of the repetition that was inevitable in the original talk format.